2
Based on preliminary work at Doe Run’s Brushy
Creek Mill, and with considerable testing to under-
stand the reagent system itself, it was determined that the
VisioFroth ™ system developed by Metso should be able to
provide this functionality and more to enable a step-change
improvement in Buick Mill’s flotation capabilities.
Most importantly, Metso’s OCS-4D© software pow-
ers both VisioFroth ™ and Metso’s advanced process con-
trol (APC) on crushing and grinding. Doe Run could use
OCS-4D© to develop and apply expert flotation, expert
grinding and the much-needed integrated expert flotation
and grinding to process its regular and complex ores in the
most efficient way possible.
As such, the major upgrade project of introducing state
of the art expert control to Buick Mill began with the intro-
duction of the VisioFroth ™ system. OCS-4D© proved to
be the ideal platform for the enterprise expert control and
operating system at Buick Mill.
VISIOFROTH™ SYSTEM
Doe Run introduced Metso VisioFroth ™, a machine
vision system, first piloted at its Brushy Creek mill with
two VisioFroth ™ cameras on the zinc rougher line, then
installed at Buick Mill. It is applied in the flotation cir-
cuit for incorporating with process control to provide more
consistent monitoring and quantitative determination of
froth properties. VisioFroth ™, a product by Metso, is an
image analysis system for on-line measurement of flotation
froth properties and gives quantitative measures of the same
(Runge et al., 2007). It calculates various parameters associ-
ated with the froth phase, which are:
• Froth velocity—the speed of froth moves towards
the launder, often used to correlate to mass pull and
recovery.
• Bubble size, bubble count distribution—the size/
counts of surface bubble. This can be used to deter-
mine reagent dosing for reagents which strongly
impact bubble size or count.
• Froth texture—a method of determining repeating
patterns of froth types, mostly utilized to correlate
the effectiveness of mineral loading with the reagents
and concentrate quality.
• Collapse rate—an indicator of the superficial surface
bubble bursting rate.
• Stability—refer to the similarity between two succes-
sive frames, recently studied can be used to deter-
mine pulping cells.
• Bubble load—indirect measurement of mineral load
attached to bubbles.
• Color—three major color outputs which are RGB,
HSV, and LAB. The most common used is LAB,
Luminance (brown color pixel, Ax (green to red),
and Bx (blue to yellow).
The VisioFroth ™ system runs in the OCS-4D© soft-
ware package. The OCS-4D© software forms the heart
of the system by processing images and quantifying froth
properties which then are used for process control to maxi-
mize and optimize the flotation circuit. The OCS-4D©
software has a graphical user interface, navigator module,
data miner module, image miner module, and variables
module. The navigator module is for the user to config-
ure logic control. It is essentially an animated control deci-
sion tree which makes it easy for the user to understand
the overall control schematic/logic. The data miner module
gives the user the ability to create charts (line plot, histo-
gram, xy plot, variogram, and radar) and acts as a statistical
module. The image miner module allows the user to store
images which are collected from the video stream thus the
user can correlate images, froth properties parameters, and
plant process variables. The variables module enables the
system to connect (inputs/outputs) to other systems (e.g.,
Distributed Control System (DCS), Programmable Logic
Controller (PLC), SQL server, etc.), creates status, flags,
equations, and logical functions. OCS-4D© includes fuzzy
expert control, modelling modules, optimizer modules,
model predictive control modules, and a PID module.
It is particularly worth noting that between Buick
Mill and Brushy Creek Mill the VisioFroth ™ system and
OCS-4D©, along with the subsequent development of the
Digital One expert system, were successfully integrated with
both Rockwell DCS and Emerson DeltaV DCS systems.
OCS-4D© allowed for seamless interfacing and automa-
tion with both DCS systems in either configuration.
Doe Run Buick Mill installed 19 VisioFroth ™ cam-
eras in the lead, zinc, and copper circuits at the Buick
Concentrator (Figure 1).
The first phase of the project included installation of 7
VisioFroth ™ cameras for Zn rougher and cleaner circuits
distributed as 4 VisioFroth ™ cameras for 4 rougher banks
at the first cell of each bank and 3 VisioFroth ™ cameras for
the 3 cleaner stages at the first cell of each stage.
The second phase of the project included installation of
5 VisioFroth ™ cameras for Cu rougher and cleaner circuits
with arrangement of 1 VisioFroth ™ camera for the rougher
first cell and 4 VisioFroth ™ cameras for the first cell of each
cleaner stage.
The final phase of the project included installation of 7
VisioFroth ™ cameras for the Pb circuit with 4 VisioFroth ™
cameras installed for the first cell of each of the 4 rougher
Based on preliminary work at Doe Run’s Brushy
Creek Mill, and with considerable testing to under-
stand the reagent system itself, it was determined that the
VisioFroth ™ system developed by Metso should be able to
provide this functionality and more to enable a step-change
improvement in Buick Mill’s flotation capabilities.
Most importantly, Metso’s OCS-4D© software pow-
ers both VisioFroth ™ and Metso’s advanced process con-
trol (APC) on crushing and grinding. Doe Run could use
OCS-4D© to develop and apply expert flotation, expert
grinding and the much-needed integrated expert flotation
and grinding to process its regular and complex ores in the
most efficient way possible.
As such, the major upgrade project of introducing state
of the art expert control to Buick Mill began with the intro-
duction of the VisioFroth ™ system. OCS-4D© proved to
be the ideal platform for the enterprise expert control and
operating system at Buick Mill.
VISIOFROTH™ SYSTEM
Doe Run introduced Metso VisioFroth ™, a machine
vision system, first piloted at its Brushy Creek mill with
two VisioFroth ™ cameras on the zinc rougher line, then
installed at Buick Mill. It is applied in the flotation cir-
cuit for incorporating with process control to provide more
consistent monitoring and quantitative determination of
froth properties. VisioFroth ™, a product by Metso, is an
image analysis system for on-line measurement of flotation
froth properties and gives quantitative measures of the same
(Runge et al., 2007). It calculates various parameters associ-
ated with the froth phase, which are:
• Froth velocity—the speed of froth moves towards
the launder, often used to correlate to mass pull and
recovery.
• Bubble size, bubble count distribution—the size/
counts of surface bubble. This can be used to deter-
mine reagent dosing for reagents which strongly
impact bubble size or count.
• Froth texture—a method of determining repeating
patterns of froth types, mostly utilized to correlate
the effectiveness of mineral loading with the reagents
and concentrate quality.
• Collapse rate—an indicator of the superficial surface
bubble bursting rate.
• Stability—refer to the similarity between two succes-
sive frames, recently studied can be used to deter-
mine pulping cells.
• Bubble load—indirect measurement of mineral load
attached to bubbles.
• Color—three major color outputs which are RGB,
HSV, and LAB. The most common used is LAB,
Luminance (brown color pixel, Ax (green to red),
and Bx (blue to yellow).
The VisioFroth ™ system runs in the OCS-4D© soft-
ware package. The OCS-4D© software forms the heart
of the system by processing images and quantifying froth
properties which then are used for process control to maxi-
mize and optimize the flotation circuit. The OCS-4D©
software has a graphical user interface, navigator module,
data miner module, image miner module, and variables
module. The navigator module is for the user to config-
ure logic control. It is essentially an animated control deci-
sion tree which makes it easy for the user to understand
the overall control schematic/logic. The data miner module
gives the user the ability to create charts (line plot, histo-
gram, xy plot, variogram, and radar) and acts as a statistical
module. The image miner module allows the user to store
images which are collected from the video stream thus the
user can correlate images, froth properties parameters, and
plant process variables. The variables module enables the
system to connect (inputs/outputs) to other systems (e.g.,
Distributed Control System (DCS), Programmable Logic
Controller (PLC), SQL server, etc.), creates status, flags,
equations, and logical functions. OCS-4D© includes fuzzy
expert control, modelling modules, optimizer modules,
model predictive control modules, and a PID module.
It is particularly worth noting that between Buick
Mill and Brushy Creek Mill the VisioFroth ™ system and
OCS-4D©, along with the subsequent development of the
Digital One expert system, were successfully integrated with
both Rockwell DCS and Emerson DeltaV DCS systems.
OCS-4D© allowed for seamless interfacing and automa-
tion with both DCS systems in either configuration.
Doe Run Buick Mill installed 19 VisioFroth ™ cam-
eras in the lead, zinc, and copper circuits at the Buick
Concentrator (Figure 1).
The first phase of the project included installation of 7
VisioFroth ™ cameras for Zn rougher and cleaner circuits
distributed as 4 VisioFroth ™ cameras for 4 rougher banks
at the first cell of each bank and 3 VisioFroth ™ cameras for
the 3 cleaner stages at the first cell of each stage.
The second phase of the project included installation of
5 VisioFroth ™ cameras for Cu rougher and cleaner circuits
with arrangement of 1 VisioFroth ™ camera for the rougher
first cell and 4 VisioFroth ™ cameras for the first cell of each
cleaner stage.
The final phase of the project included installation of 7
VisioFroth ™ cameras for the Pb circuit with 4 VisioFroth ™
cameras installed for the first cell of each of the 4 rougher